1. Field of the Invention
The present invention generally refers to the measurement of physiological properties of a person, particularly of the heart rate when playing team sports or ball games.
2. Description of the Prior Art
The measurement of the heart rate during training is of decisive meaning for an optimum and healthy fitness and endurance training. While the manual sensing of the heart beat supplies imprecise results, conventional electrocardiogram (ECG) devices are too cost-intensive and too complex during sport.
The first wireless heart rate measuring device (also known as pulse monitor watch or pulse meter) was the portable PE 2000 of Polar Electro OY. The PE 2000 heart rate measuring device is composed of a receiver and a transmitter that is either attached by disposable electrodes or an elastic electrode belt on the chest. The receiver is a watch-like monitor that can be worn around the wrist.
The conventional heart rate measuring devices record the heart signals (R-pulses) via a transmitter worn on the chest, said pulses being output via the skin, and transmit these signals to the receiver that is worn around the wrist or that is attached on a bicycle or piece of sports equipment. The current heart rate is then continuously shown on the display of the receiver.
In the fitness sector, stationary heart rate meters are often used on the devices themselves that collect the heart rate via sensors that must be comprised for the measurement. Other devices measure the heart rate on the earlap. However, the two last mentioned measuring methods are not suitable for the competitive sports sector.
WO 07/040,878 A1 discloses a further development of the conventional heart rate measuring devices. In this publication, the electrodes are integrated into a garment to measure the heart beat. Two electrodes are located on the front side of the garment and one electrode is located on the rear side. Furthermore, a device for processing the signals measured is either integrated in the garment or can be attached on the garment for instance mechanically by means of pushbuttons.
A similar device is offered by Adidas in collaboration with Polar Electro. In this case a heart rate meter can directly be attached on the chest on a T-shirt. This system also makes a chest belt superfluous.
However, these conventional systems for measuring the heart rate are suitable to only a limited extent for persons practicing a team or ball sport. Particularly in the case of ball sport the chest portion or the entire front portion of the upper part of the body is often integrated in the game. Soccer players for instance stop a cross by the chest. The same is true for basketball players, in which the front portion of the upper part of the body often contacts the ball when stopping or passing the ball. According to this, sensors in the chest area are felt uncomfortable in such cases. Above that, sensors in the chest area are at risk of being hit by a ball. If the processing and/or transmission unit is also located in the chest area, as in the Adidas-system, the risk of injury of the player is also increased. The risk of injury is also increased by the pressure connections for being coupled to the processing unit suggested in WO 07/040,878 A1.